BDBSA Project Metadata Detail

Survey/Project Number: 771          Total No. of Sites: 0
Survey/Project Name: Vegetation Dieback Assessment Method
Abstract: Executive summary Dieback of native vegetation on Kangaroo Island, particularly mallee communities, was first observed following severe drought in 2006. Drought conditions existed across much of southern Australia since at least 2003, with a particularly dry period from 2006-2008. It is not known whether these drought conditions are due to climate change resulting from global warming. While there is significant uncertainty in predictions of future rainfall trends, predicted scenarios for southern Australia include a reduction in rainfall by 2-5% by 2030 (IPCC, CSIRO 2007). A review of climate change literature located few studies that had measured drought impacts in multi-layered sclerophyll vegetation communities analogous to the mallee and woodland communities on Kangaroo Island. The Kangaroo Island Vegetation Dieback Study aimed to establish a number of representative sites to quantify native vegetation dieback. Specific objectives were to establish a baseline (2000-2009) against which future change could be measured, and to detect and quantify any current impacts on vegetation species and communities. A range of attributes were used to quantify changes in vegetation cover, floristic composition, species richness and vegetation structure. Eight 100 x 50 metre macroplots were established across Kangaroo Island, targeting areas where vegetation dieback had previously been recorded but including additional areas to monitor a range of vegetation communities across the landscape. Where possible, sites were located in Department for Environment and Heritage (DEH) reserves, for ease of current and future access. Results indicate that at least four of the eight sites have experienced significant dieback of native vegetation species, where drought was the most likely cause, particularly mallee and coastal sites. Dieback has occurred in all structural vegetation layers, impacting on mid and understorey species and canopy trees. As in earlier studies in southern Australia and South Africa, drought related dieback varied across vegetation patches, and some flora species and families appeared to be more vulnerable to drought. Species with high proportions of dead plants at mallee sites included Epacridaceae, Proteaceae, Goodeniaceae, Leguminosae and Myrtaceae species, including several endemic Kangaroo Island taxa. There are also preliminary indications of drought impacts on critical habitat for the nationally endangered SA Glossy Black-Cockatoo at one site. In the case of two of the study sites, dieback may be largely unrelated to drought and is likely caused by vegetation senescence due to time since last fire and, in the other case, to koala browse impacts and possible presence of Phytophthora cinnamomi. Drought conditions may have contributed to the observed dieback at these sites.
 
Start Date: 01/01/2000      End Date: 01/12/2009
Survey Type: Vegetation Only
   
Study Area Description: Kangaroo Island
Objectives
         Vegetation: dates only approx - need to be updated
         Fauna: *** No fauna survey objectives recorded
Methodology
         Vegetation: 2.2 Monitoring methods 2.2.1 Survey design Climate change and drought literature provides few examples of field studies that measure dieback of multi-layered sclerophyll vegetation communities analogous to the mallee and woodland communities on Kangaroo Island. Viljoen (1995) designed field surveys to assess drought damage to selected woody species in Kruger National Park in South Africa. A belt transect method was used, with all individuals of selected species within a set distance of the transect line allocated to one of five canopy dieback classes. While this method allows flexibility in monitoring sites of varying size and habitat type, it is not suitable to detect dieback in understorey species, which was a principal focus in the Kangaroo Island study. The Kangaroo Island Vegetation Dieback Study targeted areas where vegetation dieback had previously been recorded (Mooney et al. 2007) but also included additional areas in order to monitor a range of vegetation communities across the landscape. To cover as much variability as resources would allow, sampling was stratified according to vegetation communities as defined by Ball and Carruthers (1998) and Regional Ecological Area (Table 3). Where possible sites were located in Department for Environment and Heritage (DEH) reserves, for ease of current and future access. Six sites surveyed were selected from dieback sites recorded in 2007, representing inland and coastal mallee and sheoak communities of the Eastern Plains and South Coast REAs (Be1, Wi1, De1, De2, Wc1, La1) (Table 3, Figure 4). The remaining two sites were selected to sample stringybark woodland and Eucalyptus remota communities of the Seddon and Gosse Plateau REAs (Pa1, Gl1). Sites selected to sample these latter two vegetation types, typical of the ironstone plateau landscape on Kangaroo Island, were located in Parndana Conservation Park and the eastern part of Flinders Chase National Park, known as the Gosselands. The Gosselands were burnt in a November 2002 bushfire, but were one of the few parts of the large reserve estate on western Kangaroo Island that was not burnt in the December 2007 bushfires. The 2007 fires were started by a series of dry lightning strikes and decimated around 40% of the remnant vegetation on Kangaroo Island. A macroplot design was favoured because larger plots allow better representative sampling of vegetation with a high degree of understorey variation and a sometimes scattered distribution of overstorey trees. Macroplots were randomly positioned in target vegetation communities within key areas, allowing inferences to be drawn about impacts across vegetation communities (after Underwood 1997). Macroplots are 100m x 50m in size. Plots were selected using GIS to generate numbered 100 x 50m cells in target vegetation community at each study site. Plots within 100 metres of the edge of a vegetation patch or a track were eliminated, except in the case of the two coastal plots at D Estrees Bay, where target vegetation was close to main D Estrees access track (De1, De2). The study plot was chosen by generating a random number. With the exception of the site on private property at Western Cove, the south-eastern corner of all macroplots is marked with a steel stake. Sampling took place over the spring and summer of 2008-09, commencing in November 2008, with the final two plots sampled in February 2009. 2.2.2 Understorey sampling: point intercept method The point intercept method used to sample ground cover, vegetation structure and floristics is an adaptation of the method developed in Kangaroo Island Biodiversity Monitoring Program (Pisanu et al. 2006). The key points of the field method are outlined below: (see Project Notes field for more details).
         Fauna: *** No vertebrate methodology recorded

Data Distribution Rules: Public Dataset
Project Basis: Vegetation : Unclassified - pending reassessment.
Information Authority: Department for Environment and Heritage (BDBSA:Kangaroo Island) - Kingscote Office - Regional Ecologist